Stego Mastic is designed to be used as a waterproofing and vapor re ta r dant membrane for use in c onjunction with Stego Wrap 10-mil and 15-mil Vapor Retarder/Barrier. Stego Mastic can be used as an alternate to boots for pipe penetrations in Stego Wrap Vapor Barrier. Stego Mastic can also be used as a primary waterproofing for below grade walls. COMPOSITION: Stego Mastic is a medium-viscosity, water-based, polymer-modified anionic bitumin- ous /asphalt emulsion, which exhibits bonding, elongation and water- proofing characteristics. SIZE: Stego Mastic comes in 5 gallon buckets.